docs: def gauge(self, stat, value, rate=1, delta=False):
          """Set a gauge value."""
          if value < 0 and not delta:
              if rate < 1:
                  if random.random() > rate:
                      return
              with self.pipeline() as pipe:
                  pipe._send_stat(stat, '0|g', 1)
                  pipe._send_stat(stat, '%s|g' % value, 1)
          else:
              prefix = '+' if delta and value >= 0 else ''
              self._send_stat(stat, '%s%s|g' % (prefix, value), rate)